Modular underdrain systems

ABSTRACT

A modular underdrain system is disclosed. The modular underdrain system may comprise an intermediate modular component having a first peripheral side including a first mating portion and a second peripheral side including a second mating portion. The first peripheral side may comprise at least one transfer orifice. An intermediate plate member is disposed intermediate the first peripheral side and the second peripheral side along a width dimension. The intermediate plate member may comprise a metering pipe opening. A metering pipe may be sized to be positioned within the metering pipe opening.

RELATED APPLICATIONS

This application claims priority to and is a continuation application ofU.S. application Ser. No. 16/355,655, which was filed on 15 Mar. 2019and is entitled “MODULAR UNDERDRAIN SYSTEMS,” which is hereby expresslyincorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to underdrain systems for use infiltration systems.

BACKGROUND

Underdrain systems for use in filtration systems are difficult toconstruct. Further, it is challenging to formulate an underdrain systemthat achieves proper water flow during the filtering state and/or properwater flow and airflow during a cleaning state. Accordingly, an improvedunderdrain system is desirable to overcome one or more of the foregoingchallenges.

SUMMARY

Embodiments of the disclosed subject matter are provided below forillustrative purposes and are in no way limiting of the claimed subjectmatter.

Various embodiments of a modular underdrain system for use in a filtercell for filtering water are disclosed. The filter cell may comprise afilter chamber including filter media separated from an underdrainchamber by the modular underdrain system. The filter cell may furthercomprise a water injection mechanism for inputting water to be filteredinto the filter chamber and water and air injection mechanisms forinputting cleaning water and air into the underdrain chamber. Themodular underdrain system may comprise a plurality of modular componentswith each of the plurality of modular components comprising a depthdimension, a width dimension, and a length dimension with at least oneof the plurality of modular components comprising an intermediatemodular component.

One of the intermediate modular components may comprise a firstperipheral side and a second peripheral side. The first peripheral sidemay be opposite the second peripheral side along the width dimension.The first peripheral side may comprise a first mating portion, and thesecond peripheral side may comprise a second mating portion. The secondmating portion may be sized and shaped to engage with a first matingportion of an adjacent modular component. The first peripheral side maycomprise at least one transfer orifice.

The intermediate modular component may comprise a modular componentchamber bounded by an underdrain floor side and an internal side withthe underdrain floor side being offset from at least a portion of theinternal side along the depth dimension. The underdrain floor side maycomprise a plurality of slots, and the internal side may comprise ametering pipe opening.

The intermediate modular component may also comprise a metering pipesized to be positioned within the metering pipe opening. The meteringpipe opening may comprise a distributor head for positioning within themodular component chamber and an outside portion for positioning outsideof the modular component chamber. The outside portion of the meteringpipe may comprise a set of one or more proximate orifices and a set ofone or more remote orifices with the set of one or more proximateorifices being disposed closer to the modular component chamber alongthe depth dimension than the set of one or more remote orifices.

The at least one transfer orifice may comprise a first transfer orificeand a second transfer orifice with the first transfer orifice and thesecond transfer orifice being offset along the depth dimension.

The modular component chamber may comprise a first subchamber separatedby a baffle from a second subchamber with the baffle limiting fluid flowbetween the first subchamber and the second subchamber. The intermediatemodular component may further comprise a second metering pipe disposedat least partially within the second subchamber, the metering pipe beingat least partially disposed within the first subchamber. Theintermediate modular component may further comprise a second bafflespaced apart from the baffle along the length dimension of theintermediate modular component.

In various embodiments, when the modular underdrain system is in aninstalled state, the modular component chamber has a modular componentchamber cross-sectional area bounded by the internal side and theunderdrain floor side, and the intermediate modular component has anunderdrain chamber cross-sectional area bounded by the internal side,the first peripheral side, a substrate to which the first peripheralside is attached, the second peripheral side, and a first peripheralside of the adjacent modular component, the modular component chambercross-sectional area being 6% to 25% of the underdrain chambercross-sectional area.

In various embodiments, a depth dimension of the first peripheral sideis greater than a depth dimension of the second peripheral side.

In various embodiments, the first peripheral side comprises a foot forsecuring the intermediate modular component to the substrate.

In various embodiments, the intermediate modular component furthercomprises a seal positioned between the first mating portion and thesecond mating portion of the adjacent modular component.

In various embodiments, the set of one or more remote orifices comprisesa remote end orifice disposed at an end of the metering pipe most remotefrom the modular component chamber.

Various embodiments of a modular underdrain system comprising aplurality of modular components are disclosed. Each of the plurality ofmodular components may comprise a depth dimension, a width dimension,and a length dimension. The plurality of modular components may compriseat least one intermediate modular component. The intermediate modularcomponent may comprise a first peripheral side and a second peripheralside with the first peripheral side being opposite the second peripheralside along the width dimension. The first peripheral side may comprise afirst mating portion, and the second peripheral side may comprise asecond mating portion with the second mating portion being sized andshaped to engage with a first mating portion of an adjacent modularcomponent. The first peripheral side may comprise at least one transferorifice.

The intermediate modular component may comprise a modular componentchamber bounded by an underdrain floor side and an internal side withthe underdrain floor side being offset from at least a portion of theinternal side along the depth dimension. The underdrain floor side maycomprise a plurality of slots, and the internal side may comprise ametering pipe opening.

The intermediate modular component may also comprise a metering pipesized to be positioned within the metering pipe opening. The meteringpipe opening may comprise a distributor head for positioning within themodular component chamber and an outside portion for positioning outsideof the modular component chamber. The outside portion of the meteringpipe may comprise a set of one or more proximate orifices and a set ofone or more remote orifices with the set of one or more proximateorifices being disposed closer to the modular component chamber alongthe depth dimension than the set of one or more remote orifices.

In various embodiments, the second mating portion comprises a tang, andthe first mating portion of the adjacent modular component comprises anengaging slot.

In a number of embodiments, the at least one transfer orifice comprisesa first transfer orifice and a second transfer orifice, the firsttransfer orifice and the second transfer orifice being offset along thedepth dimension.

In various embodiments, the modular component chamber comprises a firstsubchamber separated by a baffle from a second subchamber, the bafflelimiting fluid flow between the first subchamber and the secondsubchamber.

In a number of embodiments, when the modular underdrain system is in aninstalled state, the modular component chamber has a modular componentchamber cross-sectional area bounded by the internal side and theunderdrain floor side, and the intermediate modular component has anunderdrain chamber cross-sectional area bounded by the internal side,the first peripheral side, a substrate to which the first peripheralside is attached, the second peripheral side, and a first peripheralside of the adjacent modular component, the modular component chambercross-sectional area being 6% to 25% of the underdrain chambercross-sectional area.

Various embodiments of a modular underdrain system comprising at least afirst and a second intermediate modular component are disclosed. Each ofthe first and the second intermediate modular components each maycomprise a depth dimension, a width dimension, and a length dimension.Each of the first and second intermediate modular components maycomprise a first peripheral side and a second peripheral side with thefirst peripheral side being opposite the second peripheral side alongthe width dimension. The first peripheral side may comprise a firstmating portion and the second peripheral side comprising a second matingportion with the second mating portion being sized and shaped to engagewith a first mating portion of an adjacent modular component. The firstperipheral side comprising at least one transfer orifice.

Each of the first and second intermediate modular component may comprisea modular component chamber bounded by an underdrain floor side and aninternal side with the underdrain floor side being offset from at leasta portion of the internal side along the depth dimension. The underdrainfloor side may comprise a plurality of slots, and the internal side maycomprise a metering pipe opening.

Each of the first and second intermediate modular components may alsocomprise a metering pipe sized to be positioned within a metering pipeopening. The metering pipe may comprise a distributor head forpositioning within the modular component chamber and an outside portionfor positioning outside of the modular component chamber. The outsideportion of the metering pipe may comprise a set of one or more proximateorifices and a set of one or more remote orifices with the set of one ormore proximate orifices being disposed closer to the modular componentchamber along the depth dimension than the set of one or more remoteorifices.

In various embodiments, when the first mating portion of the firstintermediate modular component is engaged with the second mating portionof the second intermediate modular component a combination of theunderdrain floor side of the first intermediate modular component andthe underdrain floor side of the second intermediate modular componentdefine a substantially flat surface.

The modular drain system may further comprise a hold down memberpositioned on or adjacent to the substantially flat surface.

The modular underdrain system may further comprise a terminating modularunderdrain component devoid of transfer orifices for engaging with thesecond intermediate modular component. The modular underdrain system mayfurther comprise a starter strip for engaging with a third intermediatemodular component.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention will become apparent from thefollowing description and appended claims, taken in conjunction with theaccompanying drawings. Understanding that these drawings depict onlyexamples of the invention thereof and are, therefore, not to beconsidered limiting of the invention's scope, particular embodimentswill be described with additional specificity and detail through use ofthe accompanying drawings in which:

FIG. 1 is a cross-sectional view of one embodiment of a portion of afilter cell, including a modular underdrain system, in a filteringstate;

FIG. 2 is a cross-sectional view of the portion of the filter cell ofFIG. 1 shown in a media cleaning state;

FIG. 3 is a cross-sectional view of a larger portion of the filter cellof FIG. 1 shown without filter media, water, or air disposed therein;

FIG. 4A is a top perspective view of a segment of an intermediatemodular component shown in FIGS. 1-3;

FIG. 4B is a bottom perspective view of the segment (i.e., a portion) ofthe intermediate modular component depicted in FIG. 4A;

FIG. 4C is a front elevational view of the segment of the intermediatemodular component shown in FIG. 4A;

FIG. 4D is a rear elevational view of the segment of the intermediatemodular component shown in FIG. 4A;

FIG. 4E is a side elevational view of the segment of the intermediatemodular component shown in FIG. 4A;

FIG. 5A is a front exploded view of the segment of the intermediatemodular component shown in FIG. 4A;

FIG. 5B is a perspective exploded view of the segment of theintermediate modular component shown in FIG. 4A;

FIG. 6A is an elevational, cross-sectional view of the segment of theintermediate modular component taken across the line 6A-6A in FIG. 4C;

FIG. 6B is an elevational, cross-sectional view of the segment of theintermediate modular component taken across the line 6B-6B in FIG. 4C;

FIG. 7 is a top perspective view of the segment of the intermediatemodular component shown in FIG. 4A with the underdrain floor sideomitted;

FIG. 8A is an elevational side view of a metering pipe of theintermediate modular component of FIG. 4A;

FIG. 8B is a cross-sectional side view of the metering pipe taken acrossthe line 8B-8B shown in FIG. 8A;

FIG. 9 is a top perspective view of one embodiment of a segment of aterminating modular component for use in a modular underdrain system;

FIG. 10A is a top perspective view of a segment of one embodiment of astarter strip for use in connection with a modular underdrain system;

FIG. 10B is a side view of the segment of the starter strip shown inFIG. 10A;

FIG. 10C is a front view of the segment of the starter strip shown inFIG. 10A;

FIG. 11A is a side cross-sectional view of the filter cell shown in FIG.3 taken across a width dimension of the filter cell;

FIG. 11B is an enlarged view of the region 11B shown in FIG. 11A;

FIG. 11C is an enlarged view of the region 11C shown in FIG. 11A;

FIG. 11D is an enlarged view of the region 11D shown in FIG. 11A;

FIG. 12A is a side cross-sectional view of the filter cell shown in FIG.3 taken across a length dimension of the filter cell;

FIG. 12B is an enlarged view of the region 12B shown in FIG. 12A;

FIG. 12C is an enlarged view of the region 12C shown in FIG. 12A;

FIG. 13A is a top perspective view of one embodiment of a hold downmember for use in a modular underdrain system;

FIG. 13B is an elevational side view of the hold down member shown inFIG. 13A;

FIG. 14A is a top perspective view of a segment of an alternativeembodiment of an intermediate modular component;

FIG. 14B is a top perspective view showing two segments of thealternative embodiment of the intermediate modular component of FIG. 14Ashown in mating engagement; and

FIG. 15 is a partial cross-sectional view of one embodiment of a filtercell including two or more adjacently positioned intermediate modularcomponents along a length dimension.

In accordance with common practice, the various features illustrated inthe drawings may not be drawn to scale. Accordingly, the dimensions ofthe various features may be arbitrarily expanded or reduced for clarity.In addition, some of the drawings may be simplified for clarity. Thus,the drawings may not depict all of the components of a given apparatus(e.g., device) or method. Finally, like reference numerals may be usedto denote like features throughout the specification and figures.

DETAILED DESCRIPTION

Various aspects of the present disclosure are described below. It shouldbe apparent that the teachings herein may be embodied in a wide varietyof forms and that any specific structure, function, or both disclosedherein is merely representative. Based on the teachings herein, oneskilled in the art should appreciate that an aspect disclosed herein maybe implemented independently of any other aspects and that two or moreof these aspects may be combined in various ways, even if thatcombination is not specifically illustrated in the figures. For example,an apparatus may be implemented, or a method may be practiced, using anynumber of the aspects set forth herein whether disclosed in connectionwith a method or an apparatus. Further, the disclosed apparatuses andmethods may be practiced using structures or functionality known to oneof skill in the art at the time this application was filed, although notspecifically disclosed within the application.

By way of introduction, the following brief definitions are provided forvarious terms used in this application. Additional definitions will beprovided in the context of the discussion of the figures herein. As usedherein, “exemplary” can indicate an example, an implementation, and/oran aspect, and should not be construed as limiting or as indicating apreference or a preferred implementation. Further, it is to beappreciated that certain ordinal terms (e.g., “first” or “second”) canbe provided for identification and ease of reference and may notnecessarily imply physical characteristics or ordering. Therefore, asused herein, an ordinal term (e.g., “first,” “second,” “third”) used tomodify an element, such as a structure, a component, an operation, etc.,does not necessarily indicate priority or order of the element withrespect to another element, but rather distinguishes the element fromanother element having a same name (but for use of the ordinal term). Inaddition, as used herein, indefinite articles (“a” and “an”) canindicate “one or more” rather than “one.” As used herein, a structure oroperation that “comprises” or “includes” an element can include one ormore other elements not explicitly recited. Thus, the terms “including,”“comprising,” “having,” and variations thereof signify “including butnot limited to” unless expressly specified otherwise. Further, anoperation performed “based on” a condition or event can also beperformed based on one or more other conditions or events not explicitlyrecited. As used in this application, the terms “an embodiment,” “oneembodiment,” “another embodiment,” or analogous language do not refer toa single variation of the disclosed subject matter; instead, thislanguage refers to variations of the disclosed subject matter that canbe applied and used with a number of different implementations of thedisclosed subject matter. An enumerated listing of items does not implythat any or all of the items are mutually exclusive and/or mutuallyinclusive, unless expressly specified otherwise.

In the figures in the specification for this application, a referencenumeral without a suffix (e.g., the suffix may comprise a lowercaseletter or a hyphen followed by a number) may refer to one or more of aparticular item, which may include a group of items. A reference numeralwith a suffix comprising a hyphen followed by a number (e.g., 110-1,110-2, 110-3, etc.) refers to a specific one of a group of items. Inthis case, the reference numeral without the suffix refers to all of theitems in the group; when reference is made to a specific one of theitems, a suffix comprising a hyphen followed by a number will beutilized. When multiple items in a group are present in a single figure,not all such items may be labeled with a reference numeral to avoid theundue proliferation of reference numerals on the figure. In addition, itshould be noted that the general reference number (i.e., the referencenumber without a suffix) may be used in the figure and in thespecification to refer to the items in the group or a reference numeralwith the suffix may be used to refer to a specific item in the group. Areference numeral with a suffix comprising a lowercase letter (e.g., 100a, 100 b, 100 c, etc.) references an item that is a variation of theitem bearing the reference numeral without the suffix (i.e., similar butnot identical to the item bearing the reference numeral without thesuffix). A suffix comprising a hyphen and a number and a suffix may beutilized together with the same reference numeral, when a specificinstance of a variation is referenced.

For this application, the phrases “secured to,” “connected to,” “coupledto,” and “in communication with” refer to any form of interactionbetween two or more entities, including mechanical, electrical,magnetic, electromagnetic, and thermal interaction and may also includeintegral formation. The phrase “attached to” refers to a form ofmechanical coupling that restricts relative translation or rotationbetween the attached objects. The phrases “pivotally attached to” and“slidably attached to” refer to forms of mechanical coupling that permitrelative rotation or relative translation, respectively, whilerestricting other relative motion.

The phrase “attached directly to” refers to a form of attachment bywhich the attached items are either in direct contact, or are onlyseparated by a single fastener, adhesive, or other attachmentmechanisms. The term “abut” refers to items that are in direct physicalcontact with each other, although the items may be attached, secured,fused, or welded together. The term “integrally formed” refers to a bodythat is manufactured integrally (i.e., as a single piece, withoutrequiring the assembly of multiple pieces). Multiple parts may beintegrally formed with each other if they are formed from a singleworkpiece. The term “offset” signifies that a center point of a firstreferenced object or feature and a center point of a second referencedobject or feature are not aligned along one or more axes

FIG. 1 is a cross-sectional view of one embodiment of a portion of afilter cell 100, including a modular underdrain system 112, in aninstalled state and also in filtering state. The filter cell 100comprises a depth dimension 116, a length dimension 120, and a widthdimension 118. It should be noted that the width dimension 118 of thefilter cell 100 is not necessarily greater or smaller than the lengthdimension 120 of the filter cell 100.

The illustrated filter cell 100 comprises a filter chamber 110 and anunderdrain chamber 111 separated by the modular underdrain system 112. Afiltering water injection mechanism (illustrated subsequently) may beutilized to inject water 130 into the filter chamber 110 for filtrationof the water 130 during a filtering state of the filter cell 100. Also,an air injection mechanism (illustrated subsequently) may be utilized toinject air into the underdrain chamber 111 during a cleaning state ofthe filter cell 100, which will be discussed in connection with FIG. 2.Also, a cleaning water injection mechanism (illustrated subsequently)may be utilized to inject water into the underdrain chamber 111 during acleaning state of the filter cell 100, which cleaning state will bediscussed in connection with FIG. 2.

Referring still to FIG. 1, filter media 132 may be disposed within thefilter chamber 110. Particulate matter in the water 130 is captured bythe filter media 132 during the filtering state, as water 130 flows inthe manner indicated by the water flow arrows 130 a. In an alternativeembodiment, other types of fluids, besides water 130, may be filteredutilizing the filter cell 100.

A plurality of intermediate modular components 140 of the modularunderdrain system 112 are illustrated in FIG. 1. Each intermediatemodular component 140 may comprise a modular component chamber 142, afirst peripheral side 144 and a second peripheral side 146. One or moreupper transfer orifices 156 and one or more lower transfer orifices 158may be disposed in the first peripheral side 144 to enable fluid to flowthrough the transfer orifices 156, 158. The transfer orifices 156, 158enable the transfer of water 130 or another fluid, such as air, betweenthe intermediate modular components 140 along the width dimension 118.

Each first peripheral side 144 may comprise a first mating portion 150,and each second peripheral side 146 may comprise a second mating portion152. The first mating portion 150 is shaped and sized to engage with asecond mating portion 152 of an adjacent intermediate modular component140. The second mating portion 152 is shaped and sized to engage with afirst mating portion 150 of an adjacent intermediate modular component140. A mating seal 153 may be positioned between the first matingportion 150 and the second mating portion 152 to form a media-tight sealunder normal operating conditions of the filter cell 100. The matingseal 153 may comprise, for example, a gasket, a sealant, caulking, orgrout. As illustrated in FIG. 1, the first mating portion 150 maycomprise a recess shaped to receive a protruding portion of the secondmating portion 152. Of course, in alternative embodiments, the firstmating portion 150 may comprise a protrusion, and the second matingportion 152 may comprise a recess. In yet other alternative embodiments,each of the first and second mating portions 150, 152 may comprise, forexample, a plurality of mating protrusions and recesses.

Normal operating conditions in the filter cell 100 range from −8 feet ofwater to +25 feet of water (−3.5 pounds per square inch (PSI) to 11PSI). In various embodiments, vacuum pressure may be applied to theunderdrain chamber 111 to induce water flow through the filter cell 100.In alternative embodiments, no vacuum pressure is utilized, and water130 may flow through the filter cell 100 solely based on the force ofgravity or a pump. In various embodiments, one or more of vacuumpressure, a pump, and gravity may be utilized for directing water 130through the filter cell 100.

As used herein, the term “media-tight” with reference to a seal or a fitrefers to a seal or a fit that is sufficiently tight to prevent thepassage of filter media 132 through the seal or fit in normal operatingconditions. Individual portions of Filter media 132 have a smallestdimension of 0.008 inches or greater.

Each first peripheral side 144 may comprise a foot 183. A fastener 181may be utilized to secure the foot 183 to a substrate 182.

Each intermediate modular component 140 may comprise one or moremetering pipes 170. Each metering pipe 170 may comprise a distributorhead 172 disposed within the modular component chamber 142. The portionof each metering pipe 170 outside of the modular component chamber 142may be referred to as the outside portion 171, and may comprise one ormore proximate orifices 176 and one or more remote orifices 178. The oneor more proximate orifices 176 are closer to the modular componentchamber 142 than the remote end 173 of the metering pipe 170, while theremote orifices 178 may be closer to the remote end 173 of the meteringpipe 170. A remote end orifice 178-1 at the remote end 173 comprises oneof the one or more remote orifices 178 and may be disposed at the remoteend 173 of the metering pipe 170.

It should also be noted that one or more baffles 143 may be positionedwithin each modular component chamber 142. The baffles 143 limit theflow of fluid (e.g., air 128 and water 130) between subchambers,separated by the baffles 143, within the modular component chamber 142.The baffles 143 aid in even distribution of the water 130 through themetering pipes 170 in a case where there are multiple metering pipes 170in a single modular component chamber 142, as will be illustratedsubsequently.

In a filtering state of the filter cell 100, injected water 130, asindicated by the water flow arrows 130 a, flows through the filterchamber 110 (with particulate matter being captured by the filter media132), passes into the modular component chamber 142 through slots(discussed subsequently), passes from the modular component chamber 142into the distributor head 172 and through the metering pipe 170, andexits from the metering pipe 170 via one or more of the proximate andremote orifices 176, 178. Thus, the apertures in the distributor head172, the proximate and remote orifices 176, 178, and the slots serve asa restriction to limit water flow through the filter cell 100.Accordingly, the number and size of the orifices 176, 178, apertures inthe distributor head 172, and the slots may be used to regulate waterflow through the filter cell 100 to, for example, regulate the time inwhich the water 130 is disposed within the filter chamber 110.

FIG. 2 is a cross-sectional view of the portion of the filter cell 100of FIG. 1 shown in an installed state and also in a media cleaningstate. As indicated previously, the filter cell 100 comprises a depthdimension 116, a width dimension 118, and a length dimension 120.

Periodically, it may be necessary to clean the filter media 132 asparticulate matter accumulates on the filter media 132. Thus, an airinjection mechanism, illustrated subsequently, may be utilized to injectair 128 into the underdrain chamber 111. A cleaning water injectionmechanism, illustrated subsequently, may be utilized to inject water 130into the underdrain chamber 111 during the cleaning state. Air 128 andwater 130 may flow through one or more of the proximate and remoteorifices 176, 178 (including the remote end orifice 178-1 at the remoteend 173) of the metering pipes 170. The mixture of air 128 and water 130may then proceed generally along a depth dimension 116 through themetering pipes 170 and exit the distributor heads 172 into the modularcomponent chamber 142. Thereafter, the air 128 and water 130 may flowthrough slots (which will be illustrated subsequently) in the modularcomponent chamber 142 and enter into the filter chamber 110. The air 128and water 130 striking the filter media 132 may serve to dislodgecaptured particulate matter. This flow pattern is illustrated with theairflow and water flow arrows 128 a, 130 a shown in FIG. 2.

Restricted flow caused by the size and positioning of the proximate andremote orifices 176, 178, the openings in the distributor head 172, andthe slots in the modular component chamber 142 limit the flow of air 128into the filter chamber 110, thus resulting in an air blanket 180disposed adjacent to the modular component chamber 142. A mixture of air128 and water 130 may occur, for example, below the air blanket 180,within the filter chamber 110, within the metering pipes 170, and withinthe modular component chamber 142. It should also be noted that theupper transfer orifices 156 facilitate the movement of air 128 betweenthe intermediate modular components 140, as illustrated in FIG. 2.Furthermore, the lower transfer orifices 158 enable water 130 to flowbetween the intermediate modular components 140 during the cleaningstate.

In the case where there are multiple metering pipes 170 disposed withina modular component chamber 142, baffles 143 within each modularcomponent chamber 142 may be utilized to even the flow of air 128through the slots into the filter chamber 110. Without the baffles 143,even distribution of the air 128 through the filter chamber 110 isdifficult to achieve, for example, causing more air 128 to pass throughone side of the modular underdrain system 112 such that only a portionof the filter media 132 may adequately be cleaned during the cleaningstate.

FIG. 3 is a cross-sectional view of a larger portion of the filter cell100 of FIG. 1 shown without filter media 132, water 130, or air 128disposed therein. The filter cell 100 and the modular underdrain system112 in in FIG. 3 are shown in an installed state. As indicated in FIG.3, the modular underdrain system 112 comprises a plurality ofintermediate modular components 140 each extending along a lengthdimension 120 of the filter cell 100. As indicated previously, eachintermediate modular component 140 may comprise, for example, one ormore proximate and remote orifices 176, 178, and one or more upper andlower transfer orifices, 156, 158.

Each intermediate modular component 140 may also comprise an underdrainfloor side 206, in which are disposed a series of slots 210. The slots210 may be laser cut and must be sufficiently narrow such that thefilter media 132 cannot pass through a slot 210. The slots 210 will bediscussed in additional detail subsequently. In various alternativeembodiments, each slot 210 may comprise a series of circular openings,or openings of other shapes, again being sufficiently narrow to precludethe passage of filter media 132 through the slot 210. The intermediatemodular components 140 may be made, for example, of stainless steel.

The underdrain floor sides 206 of the intermediate modular components140 define a substantially flat surface 96. In various embodiments,substantially flat signifies that there are no apertures or gaps greaterthan 2 inches across each of the width and length dimensions 118, 120,and no variation in the substantially flat surface greater than 2 inchesalong the depth dimension 116 of the filter cell 100.

A first end seal 192 may be held in place by a hold down member 190,which is secured by a plurality of hold down brackets 191. At theopposite end of the intermediate modular components 140, a second holddown bracket (not shown in FIG. 3) may comprise a part of the modularunderdrain system 112. The first end seal 192 may form a media-tightseal adjacent to the hold down member 190. The first end seal 192 maycomprise, for example, grout or a gasket. Also, one embodiment of astarter strip 95 may be positioned on one side of the modular underdrainsystem 112. The starter strip 95 will be explained in detailsubsequently.

In addition, one embodiment of an air injection mechanism 103 is alsoillustrated. The air injection mechanism 103 comprises a main conduit200 positioned within a flume 147 with risers 202 extending from themain conduit 200. As noted previously, the air injection mechanism 103injects air 128 into the filter cell 100 during a cleaning state. Morespecifically, the air injection mechanism 103 injects air 128 into theunderdrain chamber 111. It should be noted, once again, that the airinjection mechanism 103 shown in FIG. 3 is only illustrative, and airinjection mechanisms of many types may be utilized in connection withthe filter cell 100.

One embodiment of a filtering water injection mechanism 102 forinjecting water 130 to be filtered into the filter chamber 110 is alsoillustrated. The filtering water injection mechanism 102 may comprise agravity and/or pump driven system for injecting water 130 into thefilter chamber 110. In addition, a vacuum system (not shown) may bepositioned within the underdrain chamber 111 (or elsewhere) for drawingwater 130 through the filter cell 100 or toward the underdrain chamber111. In an alternative embodiment, a filtering water injection mechanismmay comprise one or more troughs (not shown) that may be filled by a setof one or more conduits, with the water spilling from the one or moretroughs into the filter chamber 110.

In addition, the filter cell 100 may also comprise a cleaning waterinjection mechanism 104. The cleaning water injection mechanism 104 maycomprise a gravity-driven and/or pump-driven mechanism for injectingwater 128 into the underdrain chamber 111 in the cleaning state. Invarious embodiments, the cleaning water injection mechanism 104 deliverswater into the flume 147. In the embodiment illustrated in FIG. 3, thecleaning water injection mechanism 104 is disposed within or adjacent tothe flume 147. Because of the perspective of the view provided in FIG.3, the cleaning water injection mechanism 104 is referenced but notvisible in FIG. 3. One embodiment of the cleaning water injectionmechanism 104 is, however, visible, for example, in FIG. 11A.

FIGS. 4A-4E, 5A-5B, 6A-6B, and 7 depict various views of a segment(i.e., portion) of an intermediate modular component 140 a. The segmentof the intermediate modular component 140 a illustrated in FIGS. 4A-4Eand 5A-5B comprises only a portion of the intermediate modularcomponents 140 illustrated in FIGS. 1-3. The segment of the intermediatemodular component 140 a includes a depth dimension 116 a, a widthdimension 118 a, and a length dimension 120 a. The segment of theintermediate modular component 140 a is included in these figures inorder to more clearly illustrate the components of the intermediatemodular components 140. In practice, an intermediate modular component140 may be longer or shorter along the length dimension 120 a than theintermediate modular components 140 or the segment of the intermediatemodular components 140 a illustrated in the figures. The illustrationsprovided serve only as examples and are not exhaustive of theproportions or dimensions of the intermediate modular components 140.While the segment of the intermediate modular component 140 a isdiscussed in connection with these figures, the discussion appliesequally to an intermediate modular component 140.

FIGS. 4A-4E and 5A-5B will be discussed concurrently. The segment of theintermediate modular component 140 a comprises a first peripheral side144, an underdrain floor side 206, a second peripheral side 146, aninternal side 207 (sometimes referred to as an intermediate plate member207), and one or more metering pipes 170. The underdrain floor side 206and the internal side 207 define a modular component chamber 142. One ormore baffles 143 may be positioned within the modular component chamber142. The baffles 143 may define a series of subchambers, which will bediscussed subsequently.

As indicated previously, the first peripheral side 144 may comprise oneor more upper transfer orifices 156 and one or more lower transferorifices 158. As indicated previously, the transfer orifices 156, 158enable air 128 and water 130 to flow between segments of theintermediate modular components 140 a. The upper transfer orifices 156are disposed closer to the modular component chamber 142 along the depthdimension 116 a than the lower transfer orifices 158. A relativeposition of the upper transfer orifices 156 and the lower transferorifices 158 along the depth dimension 116 a may be ascertained withreference to a center point of each transfer orifice 156, 158(regardless of the size of each transfer orifice 156, 158) along thedepth dimension 116 a. During the cleaning state when an air blanket 180is present, the lower transfer orifices 158 may enable water 130 to movebetween segments of intermediate modular components 140 a, while theupper transfer orifices 156 enable air 128 to move between segments ofintermediate modular components 140 a. The first peripheral side 144 mayfurther comprise a first mating portion 150 for engaging with a secondmating portion 152 of a segment of an adjacent intermediate modularcomponent 140 a or a terminating modular component (which will beexplained subsequently). The first peripheral side 144 may include afoot 183 comprising openings 222 in which fasteners may be positioned tosecure the intermediate modular component 140 to a substrate 182.

The underdrain floor side 206 comprises a series of slots 210. Asindicated previously, the slots 210 may be arranged in variousconfigurations other than the configuration shown in the figures. Forexample, the slots 210 may be arranged diagonally with respect to alength dimension 120 a or extend along a length dimension 120 a of thesegment of the intermediate modular component 140 a. Also, each slot 210may comprise a series of smaller openings, such as circular or squareopenings. As noted previously, the slots 210 must be sufficiently smallto prevent passage of filter media 132 through the slots 210, but allowwater 130 and air 128 to pass through the slots 210. In one embodimentthe slots 210 have a width 229 of 0.007 inches plus or minus 0.001inches. In applications in which either a gravel support bed or directmedia is utilized within the filter chamber 110, the slots 210 could beup to 0.125 inches in width 229. Thus, the width 229 of the slots 210may be affected by the type of filter media 132 employed within thefilter cell 100.

The internal side 207 may comprise one or more metering pipe openings227, in which a metering pipe 170 may be positioned. In one embodiment,the first peripheral side 144, the underdrain floor side 206, and thesecond peripheral side 146 may be integrally formed, while the internalside 207 may be separately formed. As illustrated, fasteners 220 may beused to secure the internal side 207 to the underdrain floor side 206. Afirst lateral chamber seal 224 and a second lateral chamber seal 225 maybe utilized to create a media-tight seal for the modular componentchamber 142 (i.e., between the internal side 207 and the firstperipheral side 144 and the second peripheral side 146). The fasteners220 may also be employed to secure baffles 143 within the modularcomponent chamber 142.

The second peripheral side 146 comprises a second mating portion 152 forengaging with a first mating portion 150 of an adjacent segment of anintermediate modular component 140 a or a starter strip 95. As notedabove, both the first and second mating portions 150, 152 may beconfigured in various ways to form a media-tight fit when used inconnection with a mating seal 153. It should be noted that the matingseal 153 may comprise a gasket, sealant, caulking, grout, or any othertype of material capable of forming a media-tight seal.

As indicated previously, one or more metering pipes 170 may bepositioned at least partially within the modular component chamber 142.In particular, a distributor head 172 of each metering pipe 170 may bepositioned within the modular component chamber 142. The distributorhead 172 may comprise, in various embodiments, a distributor head plate242, a plurality of fasteners 240, and distributor head spacers 228,which will be explained in greater detail hereafter. A locking nut 230may be used to secure the distributor head 172 within the modularcomponent chamber 142. The metering pipe 170 may comprise a set of oneor more proximate orifices 176 and a set of one or more remote orifices178. A center point of each of the proximate orifices 176 (along thedepth dimension 116 a) are positioned closer to the distributor head 172(or the modular component chamber 142) than a remote end 173 of themetering pipe 170. In contrast, a center point of each of the remoteorifices 178 (again along the depth dimension 116 a) is positionedcloser to the remote end 173 of the metering pipe 170 than to thedistributor head 172 (or the modular component chamber 142). As notedabove, one of the remote orifices 178 comprises a remote end orifice178-1 which is located at the remote end 173 of the metering pipe 170.

FIGS. 6A, 6B, and 7 will be discussed concurrently. It should be notedthat FIG. 6A is an elevational, cross-sectional view of the segment ofthe intermediate modular component 140 a taken across the line 6A-6A inFIG. 4C; FIG. 6B is an elevational, cross-sectional view of the segmentof the intermediate modular component 140 a taken across the line 6B-6Bin FIG. 4C; and FIG. 7 is a top perspective view of the segment of theintermediate modular component 140 a shown in FIG. 4A with theunderdrain floor side 206 omitted to better illustrate subchambers.

As illustrated in these figures, the segment of the intermediate modularcomponent 140 a may comprise a first baffle 143-1 and a second baffle143-2, which divide the modular component chamber 142 into a firstsubchamber 145-1, a second subchamber 145-2, and a third subchamber145-3. It should be noted that the number of baffles 143 and subchambers145 may be varied within the scope of the disclosed subject matter.

The baffles 143 limit the flow of fluid (e.g., water 130 and air 128)between the subchambers 145. This limitation results in, for example, amore even distribution of air 128 during the cleaning state such that alarge portion of the air proceeding up through an associated meteringpipe 170 (through the distributor heads 172) will remain within theassociated subchamber 145 and exit from the associated slots 210 withinthe subchamber 145. In the absence of the baffles 143, the air 128 maymove to a side or portion of the filter cell 100, resulting in unevendistribution of the cleaning effect of the air 128.

Referring now to FIGS. 8A-8B, FIG. 8A is an elevational side view of ametering pipe of the intermediate modular component of FIG. 4A, and FIG.8B is a cross-sectional side view of the metering pipe taken across theline 8B-8B shown in FIG. 8A. Each metering pipe 170 may comprise anoutside portion 171 (the portion of the metering pipe 170 outside of themodular component chamber 142 when attached thereto) and a distributorhead 172. The distributor head 172 comprises a distributor head plate242, an offset portion 243, one or more fasteners 240 and one or moredistributor head spacers 228. The one or more fasteners 240 are used tosecure the distributor head 172 to the offset portion 243. One or moredistributor head spacers 228 are positioned between the offset portion243 and the distributor head plate 242 to define one or more lateralapertures 260 (between the distributor head spacers 228) through whichair 128 and water 130 may pass into and out of the metering pipe 170.The outside portion 171 may comprise one or more proximate orifices 176and one or more remote orifices 178. As noted, the remote end orifice178-1 at the remote end 173 is one of the remote orifices 178. Asindicated previously, a locking nut 230 may be used to secure themetering pipe 170 to the internal side 207 at least partially within themodular component chamber 142.

The metering pipe 170 may be embodied in various ways other than asshown in the figures. For example, the metering pipe 170 may be devoidof lateral apertures and may include one or more apertures on otherpositions on the metering pipe 170, such as on the top of the meteringpipe 170 (i.e., an opening on the end of the metering pipe 170 oppositethe remote end 173). Also, the positioning, number and size of theproximate and remote orifices 176, 178 may be varied within the scope ofthe disclosed subject matter.

FIG. 9 is a top perspective view of one embodiment of a segment of aterminating modular component 140 b for use in a modular underdrainsystem 112. It should be noted that the term “segment” indicates thatthe segment of the terminating modular component 140 b comprises only aportion of a terminating modular component. Thus, in practice, aterminating modular component may be longer or shorter than theillustrated segment of the terminating modular component 140 b, and mayinclude, for example, different numbers of subchambers 145 and/ormetering pipes 170. Thus, while the segment of the terminating modularcomponent 140 b, is discussed in connection with FIG. 9, the discussionapplies equally to a terminating modular component.

The segment of the terminating modular component 140 b is similar to thesegment of the intermediate modular component 140 a with the exceptionthat transfer orifices 156, 158 are omitted from the segment of theterminating modular component 140 b. This is because the segment of theterminating modular component 140 b is designed to be positioned at anoutside edge of the modular underdrain system 112. The transfer orifices156, 158 are designed to enable air 128 and water 130 to transferbetween adjacent modular components. As a result, the transfer orifices156, 158 are omitted from the first peripheral side 144 a of the segmentof the terminating modular component 140 b. Beyond the absence of thetransfer orifices 156, 158, the segment of the terminating modularcomponent 140 b and the segment of the intermediate modular component140 a may otherwise be identical or similar in various embodiments.

The second mating portion 152 of the segment of the terminating modularcomponent 140 b is shaped and sized to engage with a first matingportion 150 of an adjacent segment of an intermediate modular component140 a. The terminating modular component will be discussed further inconnection with FIGS. 11A and 11B.

FIGS. 10A-10C comprise various views of a segment of one embodiment of astarter strip 95 a for use in connection with a modular underdrainsystem 112 and will be discussed concurrently. It should be noted thatthe term “segment” indicates that the segment of the starter strip 95 acomprises only a portion of a starter strip 95. Thus, in practice, astarter strip 95 may be longer or shorter than the illustrated segmentof the starter strip 95 a. Thus, while the segment of the starter strip95 a is discussed in connection with these figures, the discussionapplies equally to a starter strip 95.

The illustrated segment of a starter strip 95 a comprises a wallmounting plate 288 including one or more openings 289 for receivingfasteners to secure the segment of the starter strip 95 a to a wall of afilter cell 100. The segment of the starter strip 95 a may also comprisea first mating portion 150 for engaging with a second mating portion 152of a segment of an adjacent intermediate modular component 140 a. Thesegment of the starter strip 95 a may also comprise a foot 284 havingopenings 286 for receiving fasteners for securing the segment of thestarter strip 95 a to a substrate 182 of a filter cell 100.

The segment of the starter strip 95 a may be embodied in various waysother than as illustrated in the figures. For example, the first matingportion 150 of the segment of the starter strip 95 a may comprise aprotruding portion rather than a recessed portion.

FIGS. 11A-11D comprise various cross-sectional views of the filter cell100 shown in FIG. 3 taken across a width dimension 118 of the filtercell 100 and will be discussed concurrently. As indicated previously,the filter cell 100 may comprise a depth dimension 116, a widthdimension 118, and a length dimension 120. The filter cell 100 and themodular underdrain system 112 in FIGS. 11A-11D are shown in an installedstate. The filter cell 100 in these figures is shown devoid of air 128,water 130, and filter media 132.

As illustrated, the filter cell 100 may comprise a modular underdrainsystem 112. The modular underdrain system 112 may comprise a filteringwater injection mechanism 102 an air injection mechanism 103 and acleaning water injection mechanism 104. The filtering water injectionmechanism 102 may include a pump, a vacuum, and/or gravity drivenmechanisms for injecting water 130 into the filter cell 100. Thecleaning water injection mechanism 104 may comprise a pump or gravitydriven mechanism for injecting water 128 into the underdrain chamber 111in the clean date.

An embodiment of the air injection mechanism 103 comprising a mainconduit 200 and a plurality of risers 202 disposed within a flume 147 isalso illustrated. The risers 202 distribute air 128 throughout themodular underdrain system 112 when the filter cell 100 is in a cleaningstate.

A hold down member 190 and one or more hold down brackets 191 are alsoillustrated. The hold down member 190 and one or more hold down brackets191 limit movement of an underlying seal along a depth dimension 118, aswill be illustrated and explained in connection with FIGS. 12A-12B. Theillustrated hold down brackets 191 and hold down member 190 merelycomprise illustrative embodiments of potential designs for thesecomponents. The hold down member 190 will be discussed subsequently inadditional detail.

The modular underdrain system 112 may comprise a starter strip 95 and aplurality of modular components, such as a first intermediate modularcomponent 140-1, an adjacent intermediate modular component 140-3, asecond intermediate modular component 140-2, a last intermediate modularcomponent 140-4, and a terminating modular component 140 c. A firstmating portion 150-1 of the starter strip 95 is shown in engagement witha second mating portion 152-1 of the first intermediate modularcomponent 140-1 with an inter-positioned first mating seal 153-1. Afirst mating portion 150-2 of the adjacent intermediate modularcomponent 140-3 is engaged with a second mating portion 152-2 of thesecond intermediate modular component 140-2 with an inter-positionedsecond mating seal 153-2. A first mating portion 150-3 of the lastintermediate modular component 140-4 is engaged with a second matingportion 152-3 of the terminating modular component 140 b with aninter-positioned third mating seal 153-3.

A peripheral side 144-3 of the terminating modular component 140 b is ina media-tight engagement with a terminating seal 300. The terminatingseal 300 may comprise, for example, grout or another mechanism forcreating a media-tight seal with the peripheral side 144-3 of theterminating modular component 140 b. The terminating seal 300 may alsoprovide support to the peripheral side 144-3 of the terminating modularcomponent 140 b to counterbalance fluid pressure applied to theperipheral side 144-3 of the terminating modular component 140 b when inoperation.

Referring now to the second intermediate modular component 140-2, whichis illustrated specifically in FIG. 11C. In this figure, an underdrainchamber cross-sectional area 310 and a modular component chambercross-sectional area 312 are illustrated. The underdrain chambercross-sectional area 310 is bounded by the internal side 207-1, thefirst peripheral side 144-2 of the second intermediate modular component140-2, the substrate 182 to which the first peripheral side 144-2 isattached, the second peripheral side 146-1 of the second intermediatemodular component 140-2, and a first peripheral side 144-1 of theadjacent intermediate modular component 140-3. The modular componentchamber cross-sectional area 312 is the cross-sectional area of themodular component chamber 142 of the second intermediate modularcomponent 140-2. In various embodiments, the modular component chambercross-sectional area 312 is 6% to 25% of the underdrain chambercross-sectional area 310. When the intermediate modular component 140 isconfigured in this manner, improved air and water flow patterns areachieved during both the filtering state and the cleaning state.

FIGS. 12A-12C comprise various cross-sectional views of the filter cell100 shown in FIG. 3 taken across a length dimension 120 of the filtercell 100. More specifically, the cross-sectional view is taken acrossthe second intermediate modular component 140-2 of the modularunderdrain system 112. As discussed previously, the filter cell 100comprises a depth dimension 116, a width dimension 118, and a lengthdimension 120. The filter cell 100 and the modular underdrain system 112in FIGS. 12A-12C are shown in an installed state.

In these figures, a wall mounting plate 288 of a starter strip 95 isillustrated. In addition, one embodiment of an air injection mechanism103 at least partially positioned within a flume 147 is alsoillustrated. One embodiment of a filtering water injection mechanism 102is also illustrated.

A first end seal 192-1 and a first end pipe 320-1 are positioned at oneend of the modular underdrain system 112, and a second end seal 192-2and a second end pipe 320-2 at an opposite end of the modular underdrainsystem 112 along the length dimension 120. The first end seal 192-1 andsecond end seal 192-2 may be formed of grout, gasket or any othermechanism capable of forming a media-tight seal with the starter strip95, intermediate modular components 140 and the previously illustratedterminating modular component 140 c. The first end pipe 320-1 and thesecond end pipe 320-2 comprise conduits that may serve as spacers thatmitigate displacement of the first end seal 192-1 and the second endseal 192-2 along a depth dimension 116. The first end seal 192-1 and thefirst end pipe 320-1 are held in place by a first hold down member 190-1and a set of one or more first hold down brackets 191-1. The second endseal 192-2 and the second end pipe 320-2 are held in place by a secondhold down member 190-2 and a set of one or more second hold downbrackets 191-2.

FIGS. 13A-13B comprise various views of one embodiment of a hold downmember 190 for use in a modular underdrain system 112. As illustrated,the hold down member 190 has an L-shaped side profile. In alternativeembodiments, for example, the hold down member 190 may have a U-shaped,an I-shaped, a rectangular-shaped, or a square-shaped side profile.

FIG. 14A is a top perspective view of a segment of an alternativeembodiment of an intermediate modular component 140 d. As indicatedpreviously, the term “segment” indicates that only a portion along alength dimension of the alternative embodiment of the intermediatemodular component 140 d is illustrated. In practice, the alternativeembodiment of the intermediate modular component may be shorter orgreater along a length dimension than the illustrated segment of thealternative embodiment of the intermediate modular component 140 d. Theillustrated alternative embodiment includes a different version of afirst mating portion 150 a and a second mating portion 152 a. The firstmating portion 150 a may comprise an engaging slot shaped, sized, andpositioned for engagement with the second mating portion 152 a, whichmay comprise a tang.

FIG. 14B is a top perspective view showing two segments of thealternative embodiment of the intermediate modular component 140 d-1,140 d-2 of FIG. 14A shown in engagement. As illustrated, a second matingportion 152 a of a segment of the first intermediate modular component140 d-1 is shown engaged with a first mating portion 150 a of a segmentof the second intermediate modular component 140 d-2. In addition, amating seal 153 is positioned between the segment of the firstintermediate modular component 140 d-1 and the segment of the secondintermediate modular component 140 d-2. In alternative embodiments, themating seal 153 may be located at different positions, such as on oneside of the second mating portion 152 a and adjacent to the first matingportion 150 a. Also, it should be noted that in connection with allembodiments, multiple mating seals may be used for a first matingportion and a second mating portion. As indicated previously, the firstmating portion and second mating portion may be configured in variousways to enable mutual engagement.

FIG. 15 is a partial cross-sectional view of one embodiment of a filtercell 100 a including an alternative embodiment of a modular underdrainsystem 112 b. As indicated previously, a filter cell 100 a may comprisea depth dimension 116, a width dimension 118 and a length dimension 120.The illustrated modular underdrain system 112 b may include two or moreadjacently positioned intermediate modular components 140 e-h along alength dimension 120. Further, the illustrated filter cell 100 a alsoincludes first and second offset seams 404, 406. In particular, a firstintermediate modular component 140 e is positioned adjacent to a secondintermediate modular component 140 f at a first offset seam 404. A thirdintermediate modular component 140 g is positioned adjacent to a fourthintermediate modular component 140 h at a second offset seam 406. Thefirst and second offset seams 404, 406 are offset along the lengthdimension 120 of the filter cell 100.

In addition to the first hold down member 190-1 and the first hold downbracket 191-1, the modular underdrain system 112 b includes a first seamhold down member 193-1 positioned over the first offset seam 404 (withat least one second hold down bracket 191-2 for retaining the first seamhold down member 193-1 in position), and a second seam hold down member190 b positioned over the second offset seam 406 (with at least onethird hold down bracket 191-3 for retaining the second seam hold downmember 193-2 in position). In addition, a first hold down seal 400 maybe interposed between the first seam hold down member 193-1 and thefirst offset seam 404, and a second hold down seal 402 may be interposedbetween the second seam hold down member 193-2 and a second offset seam406 to prevent or mitigate leakage through the seams 404, 406.

It should be noted that the position of offset seams 404, 406 mayalternate in consecutive modular components along the width dimension118 between a seam disposed underneath the first seam hold down member193-1 and the second seam hold down member 193-2. In alternativeembodiments, all of the seams are disposed underneath a single hold downmember 193-1, obviating the need for a second seam hold down member193-2.

Also, additional hold down brackets may be employed at opposing ends ofthe first seam hold down member 193-1 and the second seam hold downmember 193-2, which are not visible in this figure. In addition,fasteners (not shown) with one or more fastener seals or caulking may beutilized to maintain the first seam hold down member 193-1 and thesecond seam hold down member 193-2 in place.

The foregoing disclosure and associated figures provide only examples ofthe disclosed and claimed subject matter. Limitations associated withthe description and figures are not to be imputed to the claims. Forexample, in various alternative embodiments, the first peripheral side144 and the second peripheral side portion 146 are equal in length alongthe depth dimension 116 a. In yet other alternative embodiments, thesecond peripheral side 144 is greater in length than the firstperipheral side 146 along the depth dimension 116 a. In addition, amodular component 140, 140 a-h may comprise one or multiple meteringpipes. Also, each of the one or more upper transfer orifices 156, lowertransfer orifices 158, proximal orifices 176, and remote orifices 178may have various shapes, such as circular, elongated, round, in theshape of a slot, elliptical, octagonal, square, or rectangular. Invarious embodiments, the modular component chamber 142 is sealed suchthat fluid (e.g., air 128 and/or water 130) may enter and exit themodular component chamber 142 only through the slots 210 and through themetering pipe 170 during normal operating conditions of the modularunderdrain system 112 when the modular underdrain system 112 is in aninstalled state. As used herein, a “modular component,” in singular orplural form, encompasses at least intermediate modular components 140,140 a-h, starter strips 95, and terminating modular components 140 c.Thus, an “adjacent modular component,” in singular or plural form,encompasses at least an adjacent intermediate modular component 140, 140a-h, an adjacent starter strip 95, and an adjacent terminating modularcomponent 140 c.

The previous description of the disclosed aspects is provided to enableany person skilled in the art to make or use the present disclosure.Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other aspects without departing from the scope of thedisclosure. Thus, the present disclosure is not intended to be limitedto the aspects shown herein but is to be accorded the widest scopeconsistent with the principles and novel features disclosed.

1. A modular underdrain system for use in a filter cell for filteringwater, the filter cell comprising a filter chamber including filtermedia separated from an underdrain chamber by the modular underdrainsystem, the filter cell further comprising a water injection mechanismfor inputting water to be filtered into the filter chamber and furthercomprising water and air injection mechanisms for inputting cleaningwater and air into the underdrain chamber, the modular underdrain systemcomprising a plurality of modular components, each of the plurality ofmodular components comprising a depth dimension, a width dimension, anda length dimension, at least one of the plurality of modular componentscomprising an intermediate modular component, the intermediate modularcomponent comprising: a first peripheral side and a second peripheralside, the first peripheral side being opposite the second peripheralside along the width dimension, the first peripheral side comprising afirst mating portion, and the second peripheral side comprising a secondmating portion; the first peripheral side comprising at least onetransfer orifice; an intermediate plate member disposed intermediate thefirst peripheral side and the second peripheral side along the widthdimension, the intermediate plate member comprising a metering pipeopening; and a metering pipe comprising a distributor head, a set of oneor more proximate orifices, a set of one or more remote orifices, and aremote end, the metering pipe sized to be positioned within the meteringpipe opening such that the intermediate plate member is disposedintermediate the distributor head and the remote end along the depthdimension, the set of one or more proximate orifices being disposedcloser to the distributor head along the depth dimension than the set ofone or more remote orifices.
 2. The intermediate modular component ofclaim 1, wherein the second mating portion comprises a tang.
 3. Theintermediate modular component of claim 2, wherein the at least onetransfer orifice comprises a first transfer orifice and a secondtransfer orifice, the first transfer orifice and the second transferorifice being offset along the depth dimension.
 4. The intermediatemodular component of claim 3, wherein the set of one or more remoteorifices comprises a remote end orifice disposed at the remote end ofthe metering pipe, the remote end of the metering pipe comprising an endof the metering pipe most remote from the distributor head.
 5. Themodular underdrain system of claim 4, further comprising a hold downmember for engaging with the intermediate modular component to retainthe intermediate modular component in a desired location.
 6. A modularunderdrain system comprising a plurality of modular components, each ofthe plurality of modular components comprising a depth dimension, awidth dimension, and a length dimension, the plurality of modularcomponents comprising at least one intermediate modular component, theintermediate modular component comprising: a first peripheral side and asecond peripheral side, the first peripheral side being opposite thesecond peripheral side along the width dimension, the first peripheralside comprising a first mating portion, and the second peripheral sidecomprising a second mating portion; the first peripheral side comprisingat least one transfer orifice; an intermediate plate member disposedintermediate the first peripheral side and the second peripheral sidealong the width dimension, the intermediate plate member comprising ametering pipe opening; and a metering pipe comprising a distributorhead, a set of one or more proximate orifices, a set of one or moreremote orifices, and a remote end, the metering pipe sized to bepositioned within the metering pipe opening such that the intermediateplate member is disposed intermediate the distributor head and theremote end along the depth dimension, the set of one or more proximateorifices being disposed closer to the distributor head along the depthdimension than the set of one or more remote orifices.
 7. Theintermediate modular component of claim 6, wherein the second matingportion comprises a tang.
 8. The intermediate modular component of claim7, wherein the at least one transfer orifice comprises a first transferorifice and a second transfer orifice, the first transfer orifice andthe second transfer orifice being offset along the depth dimension. 9.The intermediate modular component of claim 8, wherein the set of one ormore remote orifices comprises a remote end orifice disposed at theremote end of the metering pipe, the remote end of the metering pipecomprising an end of the metering pipe most remote from the distributorhead.
 10. The modular underdrain system of claim 9, further comprising ahold down member for engaging with the intermediate modular component toretain the intermediate modular component in a desired location.
 11. Amodular underdrain system comprising at least a first and a secondintermediate modular component, the first and the second intermediatemodular components each comprising a depth dimension, a width dimension,and a length dimension, each of the first and second intermediatemodular components comprising: a first peripheral side and a secondperipheral side, the first peripheral side being opposite the secondperipheral side along the width dimension, the first peripheral sidecomprising a first mating portion, and the second peripheral sidecomprising a second mating portion; the first peripheral side comprisingat least one transfer orifice; an intermediate plate member disposedintermediate the first peripheral side and the second peripheral sidealong the width dimension, the intermediate plate member comprising ametering pipe opening; and a metering pipe comprising a distributorhead, a set of one or more proximate orifices, a set of one or moreremote orifices, and a remote end, the metering pipe sized to bepositioned within the metering pipe opening such that the intermediateplate member is disposed intermediate the distributor head and theremote end along the depth dimension, the set of one or more proximateorifices being disposed closer to the distributor head along the depthdimension than the set of one or more remote orifices.
 12. The firstintermediate modular component of claim 11, wherein the second matingportion comprises a tang.
 13. The first intermediate modular componentof claim 12, wherein the at least one transfer orifice comprises a firsttransfer orifice and a second transfer orifice, the first transferorifice and the second transfer orifice being offset along the depthdimension.
 14. The first intermediate modular component of claim 13,wherein the set of one or more remote orifices comprises a remote endorifice disposed at the remote end of the metering pipe, the remote endof the metering pipe comprising an end of the metering pipe most remotefrom the distributor head.
 15. The modular underdrain system of claim14, further comprising a hold down member for engaging with at least oneof the first and second intermediate modular components to retain the atleast one of the first and second intermediate modular components in adesired location.